highly detailed plans for a whizbang space arsenal led by the "Rods From God" -- bundles of tungsten rods fired from orbiting platforms, hurtling toward earth at 3,700 meters per second, accurate within a range of 8 meters and able to destroy even the most hardened targets

So, 3700 m/s gives 6.8 MJ/kg of energy. One tonne of TNT is 4612 MJ. So, in order to deliver a 1 tonne explosion they need to launch 674 kg of the stuff. For a one shot weapon. Now, the shuttle costs $50,000/kg to low earth orbit (source). That's $34 million dollars per megatonne. Or $30 million dollars per Fallujah strike, if you like.